The present invention relates to a semiconductor device, in particular, a technique useful for being applied to, for example, a semiconductor device including a power transistor.
Patent Literature 1 listed below describes a technique about a three-phase inverter in which a power transistor included in each arm, and a free wheel diode coupled to this power transistor in antiparallel are formed in the same semiconductor chip.
Patent Literature 1: JP 2014-110311 A
In a three-phase inverter circuit, between its power transistor and its free wheel diode that are included in a single arm, a commutation of a current (switching of a current path) is generated at the time of switching the circuit. From this matter, it is conceivable that the power transistor and the free wheel diode, which are included in the single arm, are formed in the same semiconductor chip. In this case, a parasite inductance between the power transistor and the free wheel diode can be made small so that the ringing of a waveform for the switching, which is caused by the parasite inductance, can be restrained. This manner makes it possible that the circuit realizes a high-switching action.
However, in a full bridge circuit or a half bridge circuit, the following is caused, which is different from the situation in any three-phase inverter circuit: a current commutation is generated between a diode in an upper arm (at a high-side) of the circuit and a power transistor in a lower arm (at a low-side) thereof when the circuit is switched. Thus, even in the case of applying, to a full bridge circuit or half bridge circuit, a structure in which a power transistor included in a single arm and a free wheel diode coupled to this power transistor in antiparallel are formed in the same semiconductor chip to decrease the parasite inductance, it is impossible to expect the effect of restraining the ringing of the switching waveform. In other words, in order to restrain the switching waveform ringing, which is caused by a parasite inductance, in a full bridge circuit or half bridge circuit, it is necessary to make a contrivance different from that in any three-phase inverter circuit.
Other objects and novel features of the present invention will be made evident from the description of the specification and the attached drawings.